New T4 Microsquirt Install, engine runs poorly
Posted: Mon Jun 11, 2018 2:59 pm
Thanks in advance for taking the time to read/assist.
First install of microsquirt here, not able to get engine to run well at all. Bought a motor from a friend who purchased from engine builder years ago, fresh rebuild. 2412 type 4, 280/.488 cam, large valves, 104mm pistons (builder originally specified dual 45 dells). Basically a high revving hp heat machine.
Though it is probably the worst configuration for my application (camper), price was right, and it was intended to be a temp engine while I figured out my Camper Special build. Originally attempted to use stock L-Jet, which had worked great in previous engine, ran fairly poorly with this one (assumed due to L-Jet not being able to keep up with big cam), but was able to break in the cam and get it to at least drive, if not idle. Decided it would be a good time to finally convert to MS. Originally went fuel-only, which ran (again poorly) for about 5 minutes on points, until R20 (opto) fried and lost RPM sig. Heard that is a thing. Ordered Dubshop 36-1 wheel/hall sender, paired with 032 905 106B 4 tower logic coil, wired to VR1-/sensor ground/5v vref. Checked timing with simple timing light and corrected tooth angle to 85 deg.
Smells real rich when running, has no chance of idling, basically unusable at any RPM. Engine appears to flood, and will only pop again when cranking with fuel pump fuse removed. Can get it to run poorly at about 1200 RPM, any attempt at more kills the engine. All plugs appear fouled, black carbon all over. O2 pegged full rich. There may be an issue with O2 comm, so disabled incorporate AFR target. Any ideas? I am concerned the engine itself has issues, or too wild a cam to run anything but giant carbs. Shouldn’t the basic tables at least run the engine somewhat well? Have tried 4 squirt/2 squirt in both simultaneous and alternating. Set timing fixed to 10 deg, verified with timing light. Have a dual battery setup running lithium iron/lead acid, combined voltage is usually near 14v, solar panels on top, so low voltage not an issue. Below are specs, some screenshots. Thanks!
Microsquirt v3
New Hi Z vanagon injectors
Stock L-Jet air box/TB/plenum/runners/pump/FPR (afm flapper held open by spring)
INJ 1 output wired to Cyl 1-3
INJ2 output wired to Cyl 2-4
VW 4 tower wasted spark logic coil
SPK A output wired to Cyl 1-3
SPK B output wired to Cyl 2-4
3 BAR GM MAP
GM IAT and CLT
PLX Wideband
No TPS (signal wired to sensor ground)
Vacuum referenced from plenum feed to FPR
Wired according to manual, grounded ECU/relays direct to battery, 2 relays (ECU/Everything else)
First install of microsquirt here, not able to get engine to run well at all. Bought a motor from a friend who purchased from engine builder years ago, fresh rebuild. 2412 type 4, 280/.488 cam, large valves, 104mm pistons (builder originally specified dual 45 dells). Basically a high revving hp heat machine.
Though it is probably the worst configuration for my application (camper), price was right, and it was intended to be a temp engine while I figured out my Camper Special build. Originally attempted to use stock L-Jet, which had worked great in previous engine, ran fairly poorly with this one (assumed due to L-Jet not being able to keep up with big cam), but was able to break in the cam and get it to at least drive, if not idle. Decided it would be a good time to finally convert to MS. Originally went fuel-only, which ran (again poorly) for about 5 minutes on points, until R20 (opto) fried and lost RPM sig. Heard that is a thing. Ordered Dubshop 36-1 wheel/hall sender, paired with 032 905 106B 4 tower logic coil, wired to VR1-/sensor ground/5v vref. Checked timing with simple timing light and corrected tooth angle to 85 deg.
Smells real rich when running, has no chance of idling, basically unusable at any RPM. Engine appears to flood, and will only pop again when cranking with fuel pump fuse removed. Can get it to run poorly at about 1200 RPM, any attempt at more kills the engine. All plugs appear fouled, black carbon all over. O2 pegged full rich. There may be an issue with O2 comm, so disabled incorporate AFR target. Any ideas? I am concerned the engine itself has issues, or too wild a cam to run anything but giant carbs. Shouldn’t the basic tables at least run the engine somewhat well? Have tried 4 squirt/2 squirt in both simultaneous and alternating. Set timing fixed to 10 deg, verified with timing light. Have a dual battery setup running lithium iron/lead acid, combined voltage is usually near 14v, solar panels on top, so low voltage not an issue. Below are specs, some screenshots. Thanks!
Microsquirt v3
New Hi Z vanagon injectors
Stock L-Jet air box/TB/plenum/runners/pump/FPR (afm flapper held open by spring)
INJ 1 output wired to Cyl 1-3
INJ2 output wired to Cyl 2-4
VW 4 tower wasted spark logic coil
SPK A output wired to Cyl 1-3
SPK B output wired to Cyl 2-4
3 BAR GM MAP
GM IAT and CLT
PLX Wideband
No TPS (signal wired to sensor ground)
Vacuum referenced from plenum feed to FPR
Wired according to manual, grounded ECU/relays direct to battery, 2 relays (ECU/Everything else)